Contacts arrayed inside connectors are usually placed into the contact cavity by means of a housing lance or some other device. Double lock devices are generally used in order to increase the retaining force holding these contacts inside the housing. A number of methods for latching in double lock devices has been offered ranging from a simple fitting of a protrusion in a notch to devices incorporating springy elements, such as, for example, described in the Japanese Utility Model Publication No. 1992-23440.
For example, FIG. 5 represents a cross section of a conventional connector in which a double lock device with a latching arm is used. This connector 100 consists of a housing 102, a double lock 130 and a cover 120. Contacts and the cavity in which the contacts are retained are not shown in the drawing. The double lock device 130 is of approximately rectangular shape, and in the drawing it is shown in the state when it is completely locked in the housing 102. At approximately midpoint of the double lock device 130, there are two latching arms 132 and 142 extending in opposite directions. In the vicinity of the free ends of the latching arms 132 and 142, lugs 134 and 144 respectively are provided. The double lock device 130 is inserted in the cavity 106 of the housing 102 from the side surface 104 of the housing 102. First, the lug 144 becomes engaged with a lug 108 of the housing 102, thus providing a state of temporary latching of the double lock device 130. Next, when the double lock device 130 is inserted even farther in, the lug 134 of the latching arm 132 becomes engaged with a lug 110 of the housing 102, thus completing the latching. Due to this complete latching, the contacts are prevented from being pulled out in the direction of their axes.
Rarely, but in some cases, because of a damaged contact or improper wiring, it is necessary to remove the double lock device after it has been inserted. In such cases, the latching between lugs 134 and 110 is released by bending the latching arm 132 in the direction shown by the arrow A by pushing its end by a tip of a screw driver or some other tool. However, this design has the disadvantage consisting in that the latching condition between the latching arm 132 and the lug 110 can easily resume, thus making the task of removal of the double lock device 130 rather difficult.
The double-lock connector according to this invention was conceived having in mind elimination of the above mentioned disadvantage, and it has the following structure.